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LTC1688/LTC1689

100Mbps RS485

Hot Swapable Quad Drivers

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Ultrahigh Speed:

100Mbps

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Guaranteed Propagation Delay: 8ns

Over Temperature

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Low Channel-to-Channel Skew: 500ps Typ

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Hot Swap

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Driver Outputs Maintain High Impedance in

Three-State or with Power Off

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Short-Circuit Protected: 3mA Typ Output Current

for an Indefinite Short

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Thermal Shutdown Protected

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Single 5V or 3V Supply

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Pin Compatible with LTC486/LTC487

The LTC

bus/line drivers that can operate at data rates up to

100Mbps. Propagation delay is guaranteed at 8ns

±4ns

over the full operating temperature range. These devices

operate over the full RS485 common mode range (– 7V

to 12V), and also meet RS422 requirements.

The driver outputs are Hot Swap capable, maintaining

backplane data integrity during board insertion and

removal. The drivers feature three-state outputs, maintain-

ing high impedance over the entire common mode range

(– 7V to 12V). Outputs also remain high impedance during

power-up and with the power off. A short-circuit feature

detects bus contention and substantially reduces driver

output current. Thermal shutdown circuitry protects the

parts from excessive power dissipation.

The LTC1688 allows all four drivers to be enabled together,

while the LTC1689 allows two drivers at a time to be

enabled.

The LTC1688/LTC1689 operate from a single 5V or 3V

supply and draw only 9mA of supply current.

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High Speed RS485 Twisted-Pair Drivers

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High Speed Backplane Drivers

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Complementary Clock Drivers

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STS-1/OC-1 Data Drivers

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SCSI Drivers

Hot Swap is a trademark of Linear Technology Corporation.

, LTC and LT are registered trademarks of Linear Technology Corporation.

20ns Pulse Across 100 Feet

of Category 5 UTP

20ns/DIV

2V/DIV

2V/DIV

2V/DIV

5V/DIV

1688/89 TA02

DRIVER INPUT

DRIVER OUTPUTS

RECEIVER INPUT

RECEIVER OUTPUT

CABLE DELAY

1688/89 TA01

RECEIVER

1/4 LTC1688

100

Ω

100

Ω

1/4 LTC1518

100 FT CATEGORY 5 UTP

DRIVER

50Mbps RS485 Data Connection

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO